From the beginning of times, human beings have tried to alter matter, and recently, scientists have acquired the ability to manipulate matter, the scientist ability to manipulate materials at atomic and molecular scale through the use of nanotechnology has evolved from science fiction to science reality in common life. Today, nanotechnology is being developed in order to prevent, diagnose and treat infectious diseases, with some products about to enter the clinical trial phase. Advances in this field are exponential (1-6). Interdisciplinary nanoscience and researches including chemists, physicists, biologists and engineers are concerned on the necessity of developing ecological and sustainable methods for the synthesis of nanomaterials. There is a trend of excitement to integrate green chemistry approaches in the design of environmentally benign materials and processes. Quick advances are taking place in the synthesis of biocompatible mixed oxides or metallic nanomaterials and single bimetallic oxides, as well as the surface modification thereof intended for bioactivity and nanomedicine applications. Biosynthesis of nanoparticles as an emerging ending point from nanotechnology and biotechnology interaction has been increasingly drawing attention due to the increasing necessity to develop environmentally friendly technologies regarding material synthesis. Biomolecules as reagents have been found to have a significant advantage over equivalent molecules as protective agents (7-13).
Materials properties can change notably when their particle size is reduced to a nanometer scale. In materials science “particle” is a general term for describing small solid objects having sizes ranging from the atomic scale (10−10 m) to microscopic scale (10−3 m). However, particle size is often found between 10−9 to 10−3 m. Large particles (>10−6 m) are commonly called grains (i.e. zeolites, carbon, Raney metals) and small particles (<15 nm) of mixed (metal) oxides, i.e. TiO2—SiO2, TiO2 or SiO2 are often added (14-20). All the materials consist of grains (particles) formed by agglomeration of nanoparticles.
In conventional materials, grains have a sized comprised between 100 micrometers and millimeters (mm), while nanomaterial particles are within the range of a billionth of a meter (10−9). The mean diameter of human hair is approximately one nanometer. The radius of an atom is 1 to 3 Angstrom (Å), and one nanometer is equal to 10 Å. Nanomaterials are solid, rigid, resistant and ductile at high temperatures, they are resistant to degradation, erosion and corrosion, as well as chemically very active. The physical and chemical properties of each nanomaterial or nanoparticle material are determined by the type of compounds and the interactions by which nanoparticles are functionalized; thus electron density and hydroxyl concentration in the network has an important role in the rupture of pathogenic DNA.
One of the areas where the importance of nanoparticles has increased is the disinfection field, where a particle distribution having well defined shape and size will be obtained in order to improve disinfection activity. In particular, it is necessary to obtain highly dispersed particles where most of the atoms are located on the surface. The structure includes a solid area, pore size, as well as shape and volume of pores. These parameters are also important, since they are responsible for increasing the microorganism disinfection rate. The adsorption of functional groups on the surface makes them selective to pathogenic microorganisms and the adsorption of citrus extracts confers them disinfectant power.
Although the activity can be directly related to the total contact area between the material and the organism, determination of the surface is considered an important requirement in the characterization of said material. Also, it is necessary to specify the nature of pore structure since it is responsible for controlling the transport of reagents and products.
Titanium dioxide can be found naturally in three crystalline phases: anatase, rutile, and brookite (FIG. 2). Anatase and brookite can transform into rutile at high temperatures. Anatase can irreversibly transform into rutile by heating. Several factors contribute in phase shifting, such as particle size, crystal morphology, but in particular, the influence of ions on network poisoning. Literature cites one of the three phases, anatase, as having high chemical stability and corrosion resistance, being inert to biological agents and having high specific surface area. However, the commercial titanium oxide is a mixture (Degussa P25) containing 60 to 80% anatase. The only problem in obtaining anatase is that rutile is thermodynamically more stable. Anatase and rutile structures are tetrahedral, while brookite is orthorhombic, each titanium atom is bonded to 6 almost equally distant oxygen atoms, and each oxygen atom is bonded to three titanium atoms.
The need for disinfectants and antiseptics having specific action to inactivate virus and kill bacteria, mycobacteria, mycoplasma, fungi, protozoa and spores with proven high efficiency against these and other microorganisms has increased.
This has a relationship with the increase in new infections (e.g. HIV, influenza and avian flu) and the re-emergence of previously controlled infections due to drug resistance, environmental changes and lifestyle alterations. Besides, the use of novel medical devices, which cannot be sterilized through conventional techniques, such as heat treatment, can spread some infectious diseases. Nanotechnology will have a deep impact on nosocomial infections and the diseases caused thereby, for improved diagnosis, prevention and detection, directed therapies, and antibacterial, antiviral, antimycotical, antimycobacterial and sporicidal materials. According to literature, antimycobacterial activity is closely linked to sporicidal activity mainly around the Bacillus Subtilis. 
Diagnosis technologies combine a recognition system and a detection system, comprising a small cantilever that moves over the antigen-binding site with nanowires detecting current of cell binding immunity.
For prevention, nanotechnology-based microbicides are tested against HIV and other viruses, and are now in early clinical trials. Laboratory studies on new vaccines against hepatitis B, tuberculosis, HIV, influenza and antibacterial surface coatings or materials, including those for the medical sector, look promising. These coatings can reduce the problem related to bacteria or virus adherence to hospital surfaces and have a beneficial impact on intrahospital transmission of multiresistant bacteria, virus, spores, fungi, etc., which is a serious problem not yet solved. Titanium dioxide has a specific interaction with many biological molecules, microbes, algae, cells and living tissues. Specific interactions mean that they are different from common reactions between non-viable materials and biomolecules or living tissues. Interactions are mostly beneficial from the point of view of biotechnology applications. Titanium dioxide is known to form a direct bond with living tissues that can be used in biomaterials applications. Other application fields of the titanium dioxide include biosensors, tissue engineering, genus therapy, controlled delivery of therapeutic agents, and environmental protection (21-30).
Microbial safety is still a significant concern in priority health topics, regulatory organizations, and industries around the world. Traditionally, many strategies have been used to control microorganisms. Although synthetic antimicrobials are approved in many countries, recent trends have been towards the use of natural products, which requires exploration of safe, effective and acceptable antimicrobials from alternative sources.
In recent years nanoparticle assembly for disinfection of viral particles, virus-cell interactions, and viral pathogenesis, have taken into account these approaches for the development and design of new strategies. The rotavirus is a genus of double-stranded RNA virus in the family Reoviride (double-stranded (ds)). RNA viruses are a diverse group of viruses with a wide range of hosts (humans, animals, plants, fungi and bacteria), genome segment, organization and number (one to twelve), and virion (T number, capsidae layers or turrets).
Influenza, commonly known as flu, is an infectious disease caused by ARN viruses. The type A influenza virus particle or virion is about 80-120 nm in diameter and generally approximately spherical, although filamentous shapes can occur. Unusually for a virus, the influenza type A virus genome is not a single piece of nucleic acid, but a segmented eight-pieces of antisense RNA (13.5 kilobases total), encoding 11 proteins (HA, NA, NP, M1, M2, NS1, NEP, PA, PB1, PB1-F2, PB2). The best features of these viral proteins are hemagglutinin and neuraminidase, two large glycoproteins found on the outside of viral particles. Functionalized nanoparticulate biocatalysts of the present patent break ARN bonds and protein structure of this type of virus.